CN111572984A

CN111572984A - Tubular container with outer tube and inner container

Info

Publication number: CN111572984A
Application number: CN202010406508.7A
Authority: CN
Inventors: J·费尔南德斯德门迪奥拉昆塔纳; J·I·瓦普斯塔兰达
Original assignee: CTL TH Packaging SL
Current assignee: CTL TH Packaging SL
Priority date: 2016-03-15
Filing date: 2016-04-13
Publication date: 2020-08-25
Also published as: CN108883858A; EA201892067A1; ES2632977A1; MX2018011103A; EA036813B1; JP2019511427A; CN108883858B; EA202091150A2; TW201739438A; KR20180121987A; IL261640A; CO2018010949A2; EA202091150A3; EP3431409A1; US20190112107A1; ES2632977B1; BR112018068277A2; WO2017158209A1; AR107876A1

Abstract

The invention relates to a tubular container (1) made of flexible material, comprising an outer tube (10) and an inner container (30) housed inside the outer tube (10) and intended to come into contact with a product (51) inside the container. The flexible shoulder (32) of the inner container (30) is fixed to the head (12) of the outer tube (10), leaving an intermediate cavity (7) between the outer tube (10) and the inner container (30). At least one orifice (24) communicates the intermediate chamber (7) with the outside of the tubular container (1). The head (12) may include an unvented or one-way valve. During use of the tubular container (1), the outer tube (10) may resume its shape while the inner container (30) remains compressed. The outer tube (10) and the inner container (30) are preferably made of materials that meet different requirements. The distal end (36) of the inner container (30) preferably flares outwardly against the outer tube (10).

Description

Tubular container with outer tube and inner container

This application is a divisional application filed on 2016, 13/4, under the name of 201680083619.0, entitled "tubular container having an outer tube and an inner container".

Technical Field

The present invention relates to a tubular container made of a flexible material for containing cosmetics, foods, medicines, etc., and more particularly, to a tubular container including an outer tube and an inner container contained within the outer tube.

Background

Flexible plastic tubing is widely used in the cosmetic, pharmaceutical or food industries. Flexible plastic tubes are characterized by comprising a hollow body or skirt intended to contain a product (for example, a cosmetic cream), and a head placed at one end of the skirt and intended to allow the expulsion or dosing of the product. The head may be equipped with a neck for providing an outlet for the product, a cap, and a dosing mechanism or the like. Once the tube has been filled with product, the end of the skirt opposite the head is sealed by heat transfer welding (typically by hot air, heat clamping, ultrasound, etc.).

These flexible plastic tubes are obtained by various manufacturing methods, such as extrusion, coextrusion, injection molding, etc. Also, methods are known which comprise text, graphics, patterns, etc. by directly on the flexible plastic tube or by incorporating a separate element, such as a label, thereby providing the flexible plastic tube with any informational or decorative element. For example, flexible plastic tubing can be decorated using techniques such as offset printing, flexographic printing, serigraphy, printing, self-adhesive labels, and the like. In the injection molded pipe manufacturing process, a technique known as in-mold labeling (IML) is a well known in the art for providing labels to pipes.

Despite the wide market application, there are some unsolved problems with the manufacture of flexible plastic tubing.

For example, a first problem is the difficulty in selecting the material from which the tube is made, particularly in an injection molding process. The materials used must have very specific characteristics and meet requirements such as being able to be processed, having suitable weldability, impermeability, Environmental Stress Cracking Resistance (ESCR) and the like. When it comes to the food industry, the material must also meet the strict requirements related to food contact safety, since the tubes on the market must be in direct contact with the packaged product. In the cosmetic, nutritional and pharmacological fields, the material must meet specific suitability requirements, such as non-toxicity, general migration and specific migration, etc., since the tube must often be in direct contact with the product to be ingested or applied to the body. In general, these properties and the satisfaction of these requirements are achieved by the selection and use of polymer compounds and other components, in particular in the case of pipes produced by injection molding. However, the obtaining of polymeric compounds that meet various requirements (including mechanical requirements, food contact requirements, non-toxicity requirements, processability requirements, etc.) is extremely complex and expensive. It must also be added that when polymeric compounds are used, maintaining and guaranteeing the properties of said compounds is complicated due to the tolerance differences of the basic variables of the polymers contained in the compounds (flowability, density, stiffness, etc.). The obtainment of polymers capable of balancing all the properties required for the successful manufacture and use of said pipes is therefore very complex, in particular when the pipes are injection-moulded pipes. Furthermore, the obligation to obtain polymeric compounds that meet stringent food contact or non-toxic requirements directly precludes the use of many polymers in the preparation of the compounds, which further hinders the design of polymeric compounds.

A second problem relates to a tube known in the prior art, which actually consists of two tubes, one inside the other. The solution of having one tube inside the other is generally used to obtain an airless container, i.e. a container that prevents air from entering the container in order to improve the preservation of the packaged product (for example, products such as creams without additives, essences, vitamin C, etc.). This solution is also commonly used to address the effects of tube collapse during use. In this type of tubular container, both the inner tube and the outer tube are equipped with a skirt and a head having an outlet neck. The inner and outer tubes are connected by their outlet necks. This solution has the drawback of obtaining a high reduction rate (the ability to convey out all the contents of the tube) because the tube cannot collapse completely due to the high level of rigidity of the head of the inner tube.

A third problem relates to the sealing of double-tube tubular containers, such as those mentioned in the previous paragraph, or such as dual-product containers (tubular containers consisting of an inner tube and an outer tube containing two different products, wherein the outer tube has a head with a special configuration of two output holes for the two products, so that the two products are released simultaneously and mixed together at the exact time of their application). For the assembly of the above-described double tube container, the skirt of the inner tube and the skirt of the outer tube have a significant difference in diameter so as to enable the inner tube to be assembled within the outer tube. This means that when the ends of the skirts are flattened for a bonded seal therebetween, a perfect seal between the skirts of the inner and outer tubes cannot be achieved, and thus a sealing defect occurs. More specifically, in the central region, the seal has four wall thicknesses, while there are only two on the sides. When the clamp is compressed, the walls are welded with the correct pressure in the area with four walls, while the pressure is insufficient in the area of two walls, resulting in a poor weld in the area of two walls. Furthermore, such loosening hinders the introduction of welding nozzles, which have to be adjusted very precisely within the tube.

The present invention aims to provide a new tubular container design which addresses at least one of the above problems.

Disclosure of Invention

An object of the present invention is to provide a tube container made of a flexible material for containing cosmetics, foods, medicines, etc., and a method of manufacturing the same. The tubular container includes an outer tube and an inner container. The outer tube includes a skirt and a head, wherein the head generally includes a neck, threads, etc. The inner container is then provided with a skirt and, in a preferred embodiment of the invention, a shoulder at the proximal end of the skirt of the inner container. The shoulder is an open cap, i.e. a cap with an orifice, and thus does not completely close the proximal end of the skirt of the inner container. The shoulder is flexible or deformable, preferably exhibiting plastic deformation. The inner container is housed within the outer tube, and the shoulder of the inner container is preferably secured to the interior of the head of the outer tube in a sealing manner such that the shoulder of the inner container is capable of providing a fluid seal for the inner container once the proximal end of the tubular container has been sealed. Thus, the inner vessel does not have a tube head (with neck, threads, etc.) typical of conventional flexible tubes, but instead, when welded to the outer tube, the inner vessel uses the neck, threads, etc. of the head of the outer tube to expel its contents. In other words, the inner container shares or uses the neck of the head of the outer tube. In addition, the shoulder preferably has a high deformability without compromising the welding of the shoulder to the head of the inner container. Furthermore, the shoulder is preferably made of a laminated composite material (aluminium or other material) identical or similar to the skirt of the inner container, presenting cost advantages and a very high deformability (the deformation is plastic and therefore avoids shape recovery and guarantees permanent collapse of the inner container).

A gap is defined between the inner vessel and the outer tube. Preferably, the tubular container is able to recover its original shape after use (or in other words, after pressing the tubular container to remove the product contained therein). On the other hand, the inner container is preferably kept deformed by a one-way valve which prevents air from returning to the inside of the inner container. Preferably, the one-way valve is placed in the head of the outer tube, a cap secured to the head of the outer tube, or in another component such as an applicator or pump. Further, the distal end of the inner container is preferably deformed and widened (or flared) such that it is adjacent to and in contact with the distal end of the outer tube. The outer tube and the inner container may be made of different materials, so that the inner container intended to be kept in contact with the packaged product meets the requirements relating to this function, whereas the outer tube, which keeps the outer visible, does not need to meet said requirements of the inner container, but meets the requirements relating to the function of the outer tube, such as carrying one or more decorative elements, labels, etc.

An initial advantage provided by embodiments of the invention in which at least some of the embodiments and in particular the materials of the outer tube and the inner container meet different requirements is that the choice of materials is simplified. This solves one of the main problems of injection moulding pipes and to some extent extruded pipes and other pipe manufacturing techniques that require the use of materials with high requirements and properties. For example, the use of recycled materials, in particular for the manufacture of the outer tube, is now an option, since it is now ensured that these recycled materials do not come into contact with the packaged product, so that the tubular container can comply with the legislation currently associated with the packaging of the food, pharmaceutical or cosmetic sector.

Another advantage provided by at least some embodiments of the present invention is that it may reduce the thickness of the outer tube compared to, for example, conventional injection molded tubes of the type that do not include the double tube of the present invention, because the outer tube of the present invention has only a mechanical function and does not need to be in contact with the packaged product. Such a reduction in thickness is not possible if the product comes into contact with the outer container, since its permeability is affected. By having a smaller wall thickness, the container will be more permeable and therefore not able to adequately protect the product contained therein. Thus, some product ingredients may penetrate and the properties of the product may change. In the present invention, the impermeability required for the tubular container is provided by the inner container, which may be made of a laminate (laminate composite) comprising an aluminium film or a polymeric barrier layer or simply of a single-layer structure having the necessary impermeability, wherein the permeability of the outer tube is of no consequence. A reduction of the thickness of the wall is also not possible in the case of injection-moulded tubes, since this reduction would significantly affect the complexity of obtaining a good filling of the injection-moulded cavity. To address this situation, it is known in the plastic injection molding art that articles with thinner walls can be made using higher flow polymers, however, this increase in flow often requires a change in key properties, such as Environmental Stress Crack Resistance (ESCR) resistance.

An additional advantage provided by at least some embodiments of the present invention, and in particular embodiments in which the tubular container recovers its external shape after use, is that the tubular container provides better ergonomic use. This is because, in order to extract the stored product, pressure will always be exerted on the expanded tubular container, i.e. on the container shaped as if it were completely full, making the user's hand more comfortable to handle. Another advantage of these embodiments is that the tubular container can maintain a constant appearance, i.e. as new despite repeated use, and thus can maintain an optimal appearance throughout its lifetime. This is true even in those embodiments where the tubular container is airless, because the inner container remains deformed while the outer tube returns to its original shape.

Another advantage provided by at least some embodiments of the invention and in particular embodiments in which the shoulder of the inner container is internally fixed to the head of the outer tube is that a more effective and durable fixation between the two tubes is obtained compared to conventional double-tube solutions in which each tube has a head and in which the two heads of the two tubes are assembled to each other. Furthermore, these embodiments also improve the reduction rate compared to the conventional double-tube solution, where both tubes are fixed by their respective heads. This increase in reduction rate is due to the fact that the existing solutions do not allow the entire collapse or almost the entire collapse of the head of the inner container, even if the thickness of the head of the inner container is made smaller than the head of the outer tube; in contrast, in the tubular container of the invention, the shoulder of the inner container is flexible and is preferably made of laminated plastic or metal-plastic composite and welded to the inside of the outer tube head, enabling it to collapse due to the flexibility of the shoulder.

Another advantage provided by at least some embodiments of the present invention, and in particular embodiments in which the distal end of the inner container is widened and adjacent to and in contact with the distal end of the outer tube, is that the sealing of the distal end of the tubular container is significantly improved.

According to an aspect of the present invention, there is provided a tubular container of flexible material comprising:

-an outer tube having a skirt and a head, wherein the skirt has a proximal end and a distal end, wherein the head extends from the proximal end of the skirt, and wherein the skirt and the head define an interior space communicable with an exterior of the outer tube through an aperture in the head;

-an inner container having a skirt and a flexible shoulder, wherein the skirt has a proximal end and a distal end, wherein the shoulder extends from the proximal end of the skirt, and wherein the skirt and shoulder define an interior space, and the shoulder terminates in a rim, wherein the rim has a greater thickness than the remainder of the shoulder, and defines an aperture in communication with the interior space; wherein the content of the first and second substances,

the inner container is arranged in the inner space of the outer tube and the shoulder of the inner container is fixed to the head of the outer tube via a sealing joint in the middle region of the head via a rim, the aperture of the head of the outer tube communicating with the inner space of the inner container.

Advantageously, the tubular container comprises at least one-way valve enabling fluid to leave the inner space of the inner container to the outside of the outer tube and preventing air from entering the inner space of the inner container from the outside of the outer tube.

Advantageously, the one-way valve is arranged in an aperture of the head of the outer tube.

Advantageously, the skirt of the inner container does not protrude beyond the skirt of the outer tube.

Advantageously, the sealing joint extends continuously along the entire circumference around the central longitudinal axis of the tubular container.

Advantageously, an intermediate cavity is defined between the outer tube and the inner container.

Advantageously, the intermediate cavity is radially external to the sealing joint with respect to the central longitudinal axis.

Advantageously, the shoulder of the inner container is connected to the head of the outer tube only along the sealing joint, wherein the remainder of the shoulder is radially external to the sealing joint and separate from the outer tube.

Advantageously, said intermediate chamber extends from said sealing joint to the distal end of the skirt over the entire circumference of the skirt and shoulder around the central longitudinal axis of the tubular container.

Advantageously, the distal end of the skirt of the inner container is in contact with the distal end of the skirt of the outer tube.

Advantageously, the distal end of the skirt of the inner container is in contact with the distal end of the skirt of the outer tube over the entire circumference around the central longitudinal axis.

Advantageously, the distal end of the skirt of the inner container is fixed to the distal end of the skirt of the outer tube along at least a portion of the periphery.

Advantageously, the outer tube comprises at least one orifice communicating the intermediate chamber with the outside of the outer tube.

Advantageously, a one-way valve is arranged in said aperture, said one-way valve allowing air to enter the intermediate chamber from the outside of the outer tube and preventing air from exiting from the intermediate chamber to the outside of the outer tube.

Advantageously, the intermediate chamber, the orifice and the one-way valve are located radially outside the sealed joint with respect to the central longitudinal axis.

According to a further aspect of the present invention, there is provided a method of manufacturing a tubular container made of a flexible material, comprising the steps of:

-obtaining an outer tube having a skirt and a head, wherein the skirt has a proximal end and a distal end, wherein the head extends from the proximal end of the skirt, and wherein the skirt and the head define an interior space communicable with an exterior of the outer tube through an aperture in the head;

-obtaining an inner container having a skirt and a flexible shoulder, wherein the skirt has a proximal end and a distal end, wherein the shoulder extends from the proximal end of the skirt, wherein the skirt and the shoulder define an interior space and the shoulder terminates in a rim having a thickness greater than the remainder of the shoulder and defining an orifice in communication with the interior space; wherein the content of the first and second substances,

-inserting an inner container into the inner space of the outer tube; and is

-fixing the shoulder of the inner container to the head of the outer tube via the edge by means of a sealing joint in the middle region of the head, the orifice of the head of the outer tube communicating with the inner space of the inner container.

Advantageously, the step of obtaining the outer tube comprises obtaining a skirt of the outer tube by extrusion and forming a head of the outer tube by over-moulding on the skirt of the outer tube.

Advantageously, the step of obtaining the outer tube comprises obtaining a skirt of the outer tube by injection moulding and forming a head of the outer tube by over-injection moulding on the skirt of the outer tube.

Advantageously, the step of obtaining the inner container comprises obtaining the outer tube by co-injection moulding of a skirt and a head of the outer tube.

Advantageously, the step of obtaining the inner container comprises obtaining a skirt of the inner container by extrusion and forming the shoulder of the inner container by over-moulding on the skirt of the inner container.

Advantageously, the step of obtaining the inner container comprises obtaining a skirt of the inner container by injection moulding and forming the shoulder of the inner container by over-injection moulding on the skirt of the inner container.

Advantageously, the step of obtaining the inner container comprises obtaining the inner container by co-injection moulding of a skirt and a shoulder of the inner container.

Advantageously, the step of obtaining the inner container comprises: obtaining a first film made of plastic material or metal-plastic composite, deforming the first film until obtaining a tube, sealing the adjacent edges of the tube to maintain the tubular shape, thus obtaining a skirt of the inner container; obtaining a second film made of a plastic material or a metal-plastic composite material; making an aperture in the second membrane; stamping the second film provided with the aperture, thereby forming a shoulder of the inner container; and securing the shoulder of the inner container to the skirt of the inner container.

According to a further aspect of the present invention, there is provided a tubular container made of a flexible material, comprising:

-an outer tube comprising a skirt and a head, wherein the skirt has a proximal end and a distal end, wherein the head extends from the proximal end of the skirt, and wherein the skirt and the head define an interior space communicable with an exterior of the outer tube through an aperture in the head;

-an inner container comprising a skirt having a proximal end and a distal end; wherein the content of the first and second substances,

-the inner container is arranged in the inner space of the outer tube and the distal end of the skirt of the inner container is flared outwardly and in contact with the distal end of the skirt of the outer tube.

Advantageously, the distal end of the skirt of the inner container is flared outwardly and contacts the distal end of the skirt of the outer tube along the entire circumference about the central longitudinal axis of the tubular container.

Advantageously, the distal end of the skirt of the inner container is arranged flush with the distal end of the skirt of the outer tube.

Advantageously, a section of the distal end of the skirt of the outer tube protrudes from the distal end of the skirt of the inner container.

Advantageously, the distal end of the skirt of the inner container is fixed to the distal end of the skirt of the outer tube over at least a portion of the circumference around the central longitudinal axis of the tubular container.

Advantageously, the distal end of the skirt of the inner container is fixed to the distal end of the skirt of the outer tube by welding, adhesive or a combination thereof.

According to a further aspect of the present invention there is provided a method of manufacturing a tubular container made of flexible material, comprising the steps of:

-obtaining an outer tube comprising a skirt and a head, wherein the skirt has a proximal end and a distal end, wherein the head extends from the proximal end of the skirt, and wherein the skirt and the head define an interior space communicable with an exterior of the outer tube through an aperture in the head;

-obtaining an inner container comprising a skirt, wherein the skirt has a proximal end and a distal end;

-inserting an inner container into the inner space of the outer tube; and

-flaring the distal end of the skirt of the inner container outwardly, the distal end of the skirt of the inner container remaining flared and in contact with the distal end of the skirt of the outer tube.

Advantageously, the step of expanding the distal end of the skirt of the inner container outwards comprises expanding the entire circumference of the distal end of the skirt of the inner container around the central longitudinal axis of the tubular container, the distal end of the skirt of the inner container remaining flared outwards and in contact with the distal end of the skirt of the outer tube over said entire circumference.

Advantageously, the step of outwardly expanding the distal end of the skirt of the inner container comprises inserting a tapered member into the distal end of the skirt of the inner container and deforming the distal end of the skirt of the inner container against the distal end of the skirt of the outer tube.

Advantageously, the step of inserting the inner container into the inner space of the outer tube comprises inserting the inner container until the distal end of the skirt of the inner container is flush with the distal end of the skirt of the outer tube.

Advantageously, the step of inserting the inner container into the inner space of the outer tube comprises inserting the inner container until a section of the distal end of the skirt of the outer tube protrudes from the distal end of the skirt of the inner container.

Advantageously, the method further comprises the steps of: the distal end of the skirt of the inner container is secured to the distal end of the skirt of the outer tube along at least a portion of the circumference about the central longitudinal axis of the tubular container.

Advantageously, the step of securing the distal end of the skirt of the inner container comprises welding, adhering or a combination thereof.

Advantageously, the step of obtaining the outer tube comprises obtaining the outer tube by co-injection moulding of a skirt and a head of the outer tube.

Advantageously, the step of obtaining the inner container comprises obtaining a skirt of the inner container by extrusion.

Advantageously, the step of obtaining the inner container comprises obtaining a skirt of the inner container by injection moulding.

Advantageously, the step of obtaining the inner container comprises obtaining a laminate made of plastic material or metal-plastic composite material, deforming said laminate until a tubular shape is obtained, sealing the adjacent edges of said tubular shape to maintain the tubular shape and obtaining a skirt of the inner container.

According to another aspect of the present invention there is provided a tubular container of flexible material comprising a skirt, a head and an interior space for containing a product, the tubular container comprising:

-an inner container arranged in the inner space of the outer tube and having an inner space providing at least a part of the inner space of the tubular container and communicating with the aperture of the head of the outer tube; wherein the content of the first and second substances,

-at least a portion of the inner container is made of a first material or a first combination of materials configured to meet a first requirement; and

-at least a portion of the outer tube is made of a second material or a combination of second materials that are not configured to meet the first requirement.

Advantageously, said first requirement is an impermeability requirement.

Advantageously, the first requirement is a resistance to environmental stress cracking requirement.

Advantageously, the first requirement is a delamination resistance requirement.

Advantageously, the first requirement is a food contact requirement.

Advantageously, said first requirement is a pharmacopoeia requirement.

Advantageously, the first requirement is a flexibility requirement.

Advantageously, the first requirement is a requirement of deformability.

Advantageously, the second material or combination of second materials comprises recycled materials.

Advantageously, the second material or combination of second materials is configured to meet a second requirement, which the first material or combination of first materials does not meet.

Advantageously, said second requirement is a workability requirement.

Advantageously, the second requirement is a surface appearance requirement.

Advantageously, said second requirement is a printability requirement.

Advantageously, said second requirement is a mechanical rigidity requirement.

According to a further aspect of the present invention, there is provided a method of manufacturing a tubular container made of a flexible material, the tubular container comprising a skirt, a head and an inner space for containing a product, comprising:

-obtaining a first material or a first combination of materials configured to fulfill a first requirement;

-obtaining an outer tube comprising a skirt and a head using a first material or a combination of first materials, wherein the skirt has a proximal end and a distal end, wherein the head extends from the proximal end of the skirt, and wherein the skirt and the head define an interior space, the interior space being communicable with an exterior of the outer tube through an aperture in the head;

-obtaining a second material or a combination of second materials not configured to meet the first requirement;

-obtaining an inner container comprising an inner space using a second material or a combination of second materials;

-inserting the inner container into the inner space of the outer tube, the inner space of the inner container providing at least a part of the inner space of the tubular container, and the inner space of the inner container communicating with the aperture of the head of the outer tube.

Drawings

The details of the invention may be seen in the accompanying drawings, which are not intended to limit the scope of the invention:

figure 1 shows a cross-sectional elevation view of an outer tube of a tubular container according to an embodiment of the invention, the outer tube comprising a skirt, a head and two one-way valves.

Figure 2 shows a cross-sectional elevation view of a skirt and a shoulder, which are separately manufactured to form the inner container of the tubular container according to an embodiment of the invention.

Figure 3 shows a cross-sectional elevation of the skirt and shoulder of the previous figure, joined together to form the inner container.

Figure 4 shows a sectional front view of the inner container inserted into the inner space of the outer tube.

Figure 5 shows a sectional front view of the inner container fully inserted into the inner space of the outer tube.

Figure 6 shows a cross-sectional elevation of the skirt of the outer tube and the distal end of the skirt of the inner tube in the situation of figure 5.

Figure 7 shows a sectional elevation of the conical part inserted through the distal ends of the outer and inner tubes.

Figure 8 shows a sectional elevation of the skirt of the outer tube and the distal end of the skirt of the inner tube once the conical part of figure 7 has been removed.

Figure 9 shows a cross-sectional front view of the tubular container formed by the outer tube and the inner container.

Figure 10 shows an enlarged view of the head of the outer tube, the shoulder of the inner container, in particular, and the one-way valve provided in the head of the outer tube, which communicates with the intermediate chamber between the two tubes.

Figure 11 shows a cross-sectional front view of a tubular container sealed at its distal end and containing a product inside it.

Figure 12 shows an external perspective view of the tubular container in the situation of figure 11.

Figure 13 shows a cross-sectional front view of the tubular container of figure 11, with the application of two opposing forces compressing the container to remove product from the interior of the container.

Figure 14 shows a cross-sectional front view of the tubular container of figure 11, with the subsequent application of no more force and with the outer tube having recovered its undeformed shape, while the inner container remains deformed.

Detailed Description

The present invention relates to a tube container made of a flexible material for containing cosmetics, foods, medicines, etc., and a method of manufacturing the same. Tubular containers of this type are generally characterized by comprising a body or hollow skirt for containing a product (for example, a cosmetic cream), and a head disposed at one end of the skirt to allow the expulsion or metered delivery of the product. The head may be fitted with a product outlet neck, cap, dosing mechanism, etc. Manufacturers of such tubular containers typically supply these tubular containers to a product distributor (e.g., a cosmetic product distributor) with the head of the container closed, capped, sealed and substantially finished, and the skirt at the other end open. The product marketer fills the tubular container with its product through the open end of the skirt and then seals that end of the skirt so that the tubular container and the product contained therein are ready for sale to the public.

Fig. 9 shows an example of an embodiment of a tubular container (1) made of a flexible material according to the invention. The tubular container (1) comprises a skirt (2) and a head (3), similar to other flexible tubular containers known in the art. The skirt (2) is an elongated hollow and optionally cylindrical body arranged along a central longitudinal axis (4) and having a proximal end (5) and a distal end (6). The head (3) is arranged at the proximal end (5) of the skirt (2) and provides a closure for said proximal end (5). The head (3) of the tubular container may comprise various elements, such as a connection system for attaching additional components, a partial plug that can be pierced, means for connecting closing caps of different shapes, dosing caps, dosing pumps, applicators, non-drip systems, non-return systems, etc.

As can be seen from fig. 9, the tubular container (1) of the present invention comprises an outer tube (10) and an inner container (30) accommodated within the outer tube (10).

The outer tube (10), shown in isolation in figure 1, comprises a skirt (11) and a head (12). The skirt (11) is an elongated hollow and optionally cylindrical body disposed about a central longitudinal axis (13). The skirt (11) has an interior space (14) and an inner diameter (d1), and a proximal end (15) and a distal end (16). The head (12) is in turn arranged at the proximal end (15) of the skirt (11) and closes the outer tube (10), while allowing the metered discharge of the product from the inside of the tubular container (1). In different embodiments of the invention, the head may have different designs or configurations depending on the application or use of the tubular container (1). For example, the head may have a simple outlet orifice and an external thread for connecting a threaded cap. In other embodiments, the head may have a closure system connected to the head, such as a cap, dosing pump, or otherwise. In the present embodiment, the head (12) includes a shoulder (17), a generally cylindrical platform (18) extending from the shoulder (17), and a threaded neck (19) extending from the platform (18) for receiving a threaded cap, pump, applicator or other component or mechanism (not shown). The threaded neck (19) terminates in a transverse wall (20) provided with an orifice (21). The head (12) defines an interior space (22), in this embodiment the interior space (22) extends from the interior space (14) of the skirt (11) to the aperture (21) in the transverse wall (20).

Optionally, a one-way valve (23) can be placed in the aperture (21) of the transverse wall (20), the one-way valve being of the type that allows the removal of the product from the inside of the tube towards the outside and prevents the return of the product and of the air from the outside towards the inside of the tube. For example, the non-return valve (23) shown in the figures comprises a ball (23a) sealing a conical seat (23 b). The ball (23a) has an axial freedom of movement to allow the passage of the product contained in the internal space (14,22) when pressure is exerted on the outer tube (10) and to close the passage of air from the outside to the internal space (14,22) of the tube when this pressure disappears and a region of low air pressure appears internally (as will be described later with reference to figures 13 and 14).

In certain embodiments of the invention, the outer tube (10) may include at least one aperture (24) made in the skirt (11) and/or the head (12) of the outer tube (10) to provide an air passage between the exterior of the outer tube (10) and the interior space (14,22) of the outer tube (10). For example, in the present embodiment, the apertures (24) are provided in the platform (18) of the head (12) of the outer tube (10), communicating the inner spaces (14,22) with the outer space (not numbered). In some embodiments, for example in this embodiment, a one-way valve (25) may be housed in the aperture (24), the function of the one-way valve (25) being to allow air to be introduced from outside the outer tube (10) through the aperture (24) towards the inner space (14,22), while preventing air from passing from the inner space (14,22) to outside the outer tube (10) through the aperture (24). For example, as shown in the enlarged view of fig. 10, the check valve (25) of the present embodiment is formed as a plug inserted into the orifice (24), the plug being equipped with a flexible tapered obturator (26), a distal end (lower end in the drawing) of the flexible tapered obturator (26) being opened when the air pressure from the outside of the tube is greater than the air pressure inside the tube, and the distal end (lower end in the drawing) of the flexible tapered obturator (26) being closed when the air pressure inside the tube is greater than the air pressure outside the tube. As shown in fig. 9, the orifice (24) and the one-way valve (25) of the present embodiment are arranged axially, i.e. in the direction of the central longitudinal axis (13), and are located in the region of the platform (18) adjacent the shoulder (17).

The outer tube (10) may be decorated using techniques such as offset printing, flexographic printing, serigraphy, printing, self-adhesive labels or in-mould labelling (IML).

As shown in fig. 3, the inner container (30) in turn comprises a skirt (31) and a shoulder (32). The skirt (31) is an elongated hollow and optionally cylindrical body disposed along a central longitudinal axis (33) and having an interior space (34). The skirt (31) of the inner container (30) further has a proximal end (35), a distal end (36) and an outer diameter (d2), wherein the outer diameter (d2) is preferably slightly smaller than the inner diameter (d1) of the skirt (11) of the outer tube (10). The shoulder (32) of the inner container (30) is placed at the proximal end (35) of the skirt (31) and is formed as a wall partially closing said proximal end of the skirt (31) and ending with a rim (38). The shoulder (32) is flexible and has an interior space (39). In turn, the rim (38) defines an orifice (37) communicating the inner space (39) with the outside of the inner container (30). Preferably, as in the present embodiment, the wall forming the shoulder (32) is substantially frustoconical, and the edge (38) and the hole (37) are concentric and their centres are arranged on the central longitudinal axis (33) of the inner container (30). In certain embodiments, the shoulder (32) may have a constant thickness. In other embodiments, such as those disclosed herein, the rim (38) has a greater thickness than the remainder of the shoulder (32). Embodiments are also envisaged in which the shoulder (32) comprises at least one recess or zone (not shown) of reduced thickness, for example in the shape of a ring arranged around the central longitudinal axis (33), the function of which is detailed below.

As previously mentioned, the inner container (30) is arranged inside the outer tube (10), i.e. inside the inner space (14) of the skirt (11) and inside a portion of the inner space (22) of the head (12) of the outer tube (10). As shown in fig. 9, the shoulder (32) of the inner container (30) is in contact with the head (12) of the outer tube (10) at the entire periphery of the shoulder (32), said contact being fluid-tight by means of a sealing joint (40) defined between the shoulder (32) and the head (12). Preferably, such sealing joint (40) between the shoulder (32) and the head (12) is constituted by a welded joint. The sealing joint (40) prevents fluid from passing between the edge (38) of the shoulder (32) of the inner container (30) and the head (12) of the outer tube (10). Fluid passage is prevented throughout the sealing joint (40) extending 360 ° around the central longitudinal axis (4) of the tubular container (1).

As shown, the sealing joint (40) is arranged in a radially intermediate region of the head (12) of the outer tube (10), radially closer to the central longitudinal axis (4) than the skirt (31) of the inner container (30), more particularly on the edge (27) of the platform (18) adjacent to the inner space (22). In some embodiments, this edge (27) of the head (12) of the outer tube (10) may be provided with a seat or projection (not shown) extending towards the inner space (22), the function of which is described in detail below.

Furthermore, as previously mentioned, the outer diameter (d2) of the skirt (31) of the inner container (30) is slightly smaller than the inner diameter (d1) of the skirt (11) of the outer tube (10), thus defining a gap between the skirt (11) of the outer tube (10) and the skirt (31) of the inner container (30). The difference in diameters is such that when the inner container (30) expands outwardly (as described below with reference to fig. 7 and 8), the skirt (31) of the inner container (30) has sufficient deformability to adjust to the inner diameter (d1) of the skirt (11) of the outer tube (10).

The distal end (16) of the outer tube (10) and the distal end (36) of the inner container (30) are arranged at the distal end (6) of the skirt (2) of the tubular container (1). As shown in the enlarged view of fig. 8, the skirt (31) of the inner container (30) includes a widened region (41) at the distal end (36) of the skirt (31). A widened region (41) of length (h2) is maintained adjacent to and in contact with the distal end (16) of the skirt (11) of the outer tube (10), preferably over the entire circumference of the skirt (11) of the outer tube (10) around the central longitudinal axis (4) of the tubular container (1).

In certain embodiments, the distal end (16) of the skirt (11) of the outer tube (10) and the distal end (36) of the skirt (31) of the inner container (30) are welded or adhered to each other in a contact region having a length (h 2). The weld or adhesion may span the entire circumference around the central longitudinal axis (4) or be intermittent. The weld or adhesion may span all or part of the length (h 2). The purpose of the welding or adhesion is twofold. The initial function is that of this welding or adhesion ensuring that, once the container has been filled with product, the distal end (16) of the skirt (11) of the outer tube (10) and the distal end (36) of the skirt (31) of the inner container (30) remain in contact and adjacent until the distal end (6) of the tubular container (1) is sealed. It has to be considered that, from the manufacture of the tubular container (1) of fig. 9 until it is filled with product and sealed at its distal end (6), a considerable time may elapse, the tubular container (1) may be subjected to the effects of transportation, storage, handling, etc., which may cause undesired mechanical effects on the tubular container (1). This welding or adhesion helps to ensure that contact is maintained along the length (h2) despite these potential mechanical effects, and that a tight bond is achieved between the inner container (30) and the outer tube (10) during final sealing of the distal end (6) of the tubular container (1). In the particular case of welding or adhesion along the entire periphery, the second function of this welding or adhesion is to ensure that the inner wall (10) of the distal end (16) of the skirt (11) of the outer tube (10) is perfectly welded to the outer wall of the distal end (36) of the skirt (31) of the inner container (30). In this way, the product seller only has to be concerned with the correct welding of the inner container (30) when sealing the distal end (6) of the tubular container (1) once the container has been filled with product, since the outer tube (10) is supplied in a pre-welded manner. From the perspective of the product marketer who needs to fill the container and seal the distal end (6), this solution helps the tubular container (1) to behave as if it were a single-layer tube, which significantly simplifies the sealing of the distal end (6) because the systems commonly used introduce the nozzle with very small tolerances with respect to the tube wall.

As shown in fig. 8, the above-mentioned intermediate chamber (7) is defined above the widened zone (41). Thus, as shown in fig. 8 and 9, the intermediate chamber (7) is delimited by the head (12) of the outer tube (10), the shoulder (32) of the inner container (30) and the skirt (11) of the outer tube (10) and the skirt (31) of the inner container (30).

In certain embodiments, such as the embodiment shown in the figures, the outer tube (10) and inner container (30) are dimensioned such that the distal end (16) of the skirt (11) of the outer tube (10) protrudes from the distal end (36) of the skirt (31) of the inner container (30) by a length (h1), as shown in fig. 8.

An example of a method of manufacturing a tubular container according to the present invention for manufacturing the foregoing tubular container (1) is described in detail below. Hereinafter, the method of using the tubular container (1) by the product marketer and the end user is explained in detail in order to explain the advantageous effects of the present invention.

Fig. 1 to 10 show a manufacturing sequence of a tubular container (1) according to an embodiment of the manufacturing method of the present invention.

In an initial step of the process, the above-mentioned outer tube (10) is manufactured with a skirt (11) and a head (12) as shown in fig. 1. The outer tube (10) may be manufactured in one or more stages by any conventional technique known in the art of flexible tubular container manufacture. For example, the outer tube (10) may be manufactured by extruding the skirt (11) and then overmolding the head (12). In other embodiments, the outer tube (10) may be manufactured by injection molding of the skirt (11) and then overmolding the head (12) onto the skirt (11). In another example, the entire outer tube (10) may be manufactured by co-injection molding the skirt (11) and the head (12). The outer tube (10) may be made from a formulation comprising one or more plastic materials such as polypropylene, polyethylene, copolymers, and the like. The manufacture of the outer tube (10) may include the decoration of the outer tube using techniques such as offset printing, flexographic printing, serigraphy, printing, self-adhesive labels or in-mould labelling (IML).

In another initial step of the process, an inner container (30) is manufactured having a skirt (31) and a shoulder (32), which may be performed before, after or simultaneously with the previous step. The skirt (31) and shoulder (32) may be made of plastic, metal, or a combination thereof. The skirt (31) and shoulder (32) may be manufactured together or, alternatively, may be manufactured separately and then joined together, as shown in fig. 2 and 3. More specifically, and as an example, the skirt (31) may be obtained from a plastic film (for example polyethylene), or from a metal-plastic composite film (for example an aluminium layer with an outer or inner layer made of polyethylene or polypropylene and the necessary adhesive for enabling the formation of a bond between the layers), from a plastic composite film (for example an EVOH layer with an outer and/or inner layer made of polyethylene or polypropylene, also using the necessary adhesive) or by other plastic forming techniques, for example extrusion or injection moulding. In the case of a membrane, the membrane is deformed or bent until a tubular shape (e.g., cylindrical) is obtained. The opposite longitudinal edges of the film are then welded or sealed to obtain a tubular sleeve. Welding is performed by generating heat in the welding area. The heat causes the polymers in the opposing longitudinal edges to melt and adhere to each other. Such a manufacturing method is known and used for manufacturing laminated tubes for containing for example toothpaste. Heat may be generated using conventional resistive systems or by high frequency magnetic fields (in the case of metal-plastic films) or the like. Finally, a skirt (31) is obtained by cutting a predetermined length of the tubular sleeve. Continuing with this example, the shoulder (32) of the inner container (30) can in turn be made of a plastic film (for example polyethylene), or of a metal-plastic film (for example an aluminum layer with an outer coating or inner layer made of polyethylene or polypropylene, with the necessary adhesive to enable a bond to be formed between the layers), or of a plastic composite film (for example an EVOH layer with an outer coating and/or inner layer made of polyethylene or polypropylene, with the necessary adhesive also being used). Portions of the film are cut and apertures are made in each portion. These portions are then placed in a die and a pressure or punching operation is applied to provide the shoulders with a three-dimensional cylindrical conical shape as shown in the figures, wherein the orifice of each portion constitutes an orifice (37) of the shoulder (32). Although a frustoconical shoulder (32) has been shown herein, alternative embodiments are contemplated in which the shape of the shoulder (32) may vary.

Once the skirt (31) and the shoulder (32) of the inner container (30) are obtained, the shoulder (32) is welded to the proximal end (35) of the skirt (31), as shown in fig. 3, thereby attaching the shoulder and the skirt. The welding may be performed, for example, by hot air, conduction, ultrasound, etc. In the case where both the skirt portion (31) and the shoulder portion (32) are made of a combination of plastic and metal, welding can also be performed by a high-frequency magnetic field.

Once the inner container (30) has been obtained, the inner container (30) is inserted into the outer tube (10), as shown in fig. 4. More specifically, the shoulder (32) of the inner container (30) passes through the open distal end (16) of the skirt (11) of the outer tube (10) and the inner container (30) is advanced inside the outer tube (10) and along the inner space (14) of the outer tube (10). Finally, as shown in fig. 5, the shoulder (32) of the inner container (30), more particularly the edge (38) surrounding the orifice (37), is in contact with the inner wall of the head (12) of the outer tube (10), more particularly with the inner wall of the platform (18).

The shoulder (32) of the inner vessel (30) is then welded to the head (12) of the outer tube (10), for example by hot air, conduction or high frequency (in the case where the shoulder (32) and/or the head (12) are made of a combination of plastic and metal). As previously mentioned, this welding, in addition to securing the outer tube (10) and the inner vessel (30) to each other, also provides a sealed joint (40) between the edge (38) of the shoulder (32) of the inner vessel (30) and the inner wall of the head (12) of the outer tube (10).

As shown in fig. 6, once the inner container (30) is inserted and secured to the outer tube (10), the distal ends (16,36) of the skirts (11,31) at opposite ends of the outer tube (10) and inner container (30) are radially separated from each other by a gap or distance (r 1). The distance (r1) is substantially equal to half the difference between the inner diameter (d1) of the skirt (11) of the outer tube (10) and the outer diameter (d2) of the skirt (31) of the inner container (30). Additionally, the distal end (16) of the skirt (11) of the outer tube (10) may protrude a length (h1) relative to the distal end (36) of the skirt (31) of the inner container (30), as shown. However, other embodiments are conceivable in which the distal end (16) of the skirt (11) of the outer tube (10) does not protrude from the distal end (36) of the skirt (31), i.e. in which the length (h1) is zero.

Then, as shown in fig. 7 and 8, an additional optional step is performed consisting in expanding the distal end (36) of the inner container (30) outwards. In this step, the inner container (30) and optionally the outer tube (10) are subjected to a deformation which causes the open distal end (36) of the skirt (31) of the inner container (30) to widen until the outer diameter (d2) of the open distal end (36) is substantially the same as the inner diameter (d1) of the skirt (11) of the outer tube (10) and therefore the distal end (36) of the skirt (31) of the inner container (30) rests internally on the distal end (16) of the skirt (11) of the outer tube (10). The deformation may be achieved, for example, by axially inserting a member having a gradually decreasing diameter or a conical member (50) into the open distal end (36) of the skirt (31) of the inner container (30) up to a predetermined depth. In some embodiments, heat may be applied in conjunction with the deformation to cause fusion of the distal ends (16, 36). In other embodiments, the deformation may be performed without the application of heat such that the distal ends (16,36) become adjacent and in contact. Once the tapered member (50) deforms the distal end (36) of the skirt (31) of the inner container (30), the tapered member (50) is removed. In some embodiments, such as those described herein, the distal end (16) of the skirt (11) of the outer tube (10) is not deformed. In other embodiments, the distal end (16) of the skirt (11) of the outer tube (10) is deformed and, once the tapered member (50) is removed, the distal end (16) of the skirt (11) of the outer tube (10) may return to its original cylindrical shape. In other embodiments, the distal end (16) of the skirt (11) of the outer tube (10) is deformed and does not return to its original cylindrical shape once the tapered portion (50) is removed. In any case, once the tapered portion (50) has been removed, as shown in fig. 8, the distal end (36) of the skirt (31) of the inner container (30) having a length (h2) is attached to and in contact with the skirt (11) of the outer tube (10). In some embodiments, welding or adhesive is applied along all or part of the circumference of the wall of the distal ends (16,36) of the skirt (11,31) simultaneously with or after deformation, so that these distal ends (16,36) are not only adjacent, but also attached along part or all of the circumference.

Once the distal end (16) of the skirt (11) of the outer tube (10) and the distal end (36) of the skirt (31) of the inner container (30) are brought into proximity by deformation, and optionally attached together by welding or adhesion along all or part of the periphery, the tubular container (1) of fig. 9 is obtained. The tubular container (1) is characterized in that it has an outer tube (10) for remaining visible and accessible by the consumer, and an inner container (30) for contacting the product to be stored in the tubular container (1).

Finally, if this has not already been done, a cap (not shown) or any other optional additional element is added to the tubular container (1). The tubular container (1) is then delivered to a product marketer, such as a cosmetic marketer, for the product marketer to fill the tubular container (1) with its product.

The tubular container (1) according to the invention, although consisting of two tubes (outer tube (10) and inner container (30)), has the appearance of a conventional tubular container and, more importantly, can be filled and sealed in the same way as a conventional tubular container for the product marketer. The head (12) of the outer tube (10) forms the head (3) of the tubular container (1), while the skirt (11) and the skirt (31) form the skirt (2) of the tubular container (1). The distal end (16) of the skirt (11) of the outer tube (10) and the distal end (36) of the skirt (31) of the inner container (30) are adjacent to and in contact with each other, thus providing a single opening at the distal end (6) of the skirt (2) of the tubular container (1) communicating with a single internal space of the tubular container (1), which is the internal space (34) of the inner container (30), enabling the tubular container (1) to be filled in a conventional manner.

A product marketer (e.g., a cosmetic marketer) fills the tubular container (1) with a certain product (51) (shown in fig. 11,13 and 14), such as cream, and supplies the product (51) to the interior space (34,39) of the inner container (30) through the open distal end (6) of the tubular container (1). Then, as shown in fig. 11, the distal end (6) of the skirt (2) of the tubular container (1) is welded, for example, by applying heat, high frequency, adhesive, or the like, to the skirt (2); pressure is then applied to this distal end (6) of the skirt (2) flattening the distal end (6) and sealing it in the form of a straight seal, as shown in figure 12. More specifically, the sealing is performed along a band of the distal end (6) having a height (h3) that spans part or all of the length (h2) of the widened zone (41) of the distal end (36) of the skirt (31) of the inner container (30) and, if present, the additional length (h1) of the skirt (11) of the outer tube (10), further spanning this additional length (h 1). This ensures a tight and durable bond between the two

skirts

11 and 31 along the widened zone (41) over the entire periphery of the

skirts

11 and 31 and, optionally, a seal of the end of the skirt (11) of the outer tube (10) onto the end of the skirt (11) itself along the additional length (h1) of the skirt (11) of the outer tube (10). Once welded, the product (51) is contained in the inner space of the tubular container (1), more specifically in the inner spaces (34,39) of the inner container (30), as shown in fig. 11.

Fig. 13 shows the process of extracting the product (51) from the inside of the tubular container (1) by the user. As shown, when a user wishes to dispense some product (51) from the inside of the tubular container (1), the user applies two opposing lateral forces (F), typically with the aid of the user's fingers. Two opposing lateral forces (F) collapse the outer tube (10) towards the inside of the skirt (11) and increase the pressure in the intermediate chamber (7) between the outer tube (10) and the inner container (30). In this embodiment, the one-way valve (25) of the outer tube (10) prevents the release of air from the intermediate chamber (7), and therefore the collapsing of the skirt (11) and the increase in pressure in the intermediate chamber (7) compresses the inner container (30), more specifically the skirt (31) of the inner container (30). In an alternative embodiment, one or more apertures in the outer tube (10) communicating with the intermediate chamber (7) and preferably free of valves, may allow air to escape when the outer tube (10) is compressed and thus allow the outer tube (10) to contact and push the inner container (30), causing compression of the skirt (31) of the inner container (30). When the skirt (31) of the inner container (30) is compressed, the edge (38) of the shoulder (32) of the inner container (30) remains welded to the head (12) of the outer tube (10). If the shoulder (32) of the inner container (30) includes one or more notches or areas of reduced thickness, these notches further facilitate the downward flexing of the shoulder (32) when necessary upon compression/squeezing of the skirt (31) without flexing the edge (38) of the shoulder (32) to excessively pull on the head (12) of the outer tube (10).

Compression of the skirt (31) of the inner container (30) causes an increase in pressure in the interior space (34,39) of the inner container (30). When the increase in pressure is sufficient, the product (51) begins to be removed through the aperture (37) in the shoulder (32) of the inner container (30), the interior space (22) of the head (12) of the outer tube (10), and the one-way valve (23) in the head (12) of the outer tube (10). When the user stops applying the force (F), the skirt (31) of the outer tube (30), which is elastic and tends to resume its original undeformed shape, starts to open outwards, creating a vacuum in the intermediate chamber (7). This vacuum causes air to enter from the outside through the one-way valve (25) and communicate with the intermediate chamber (7), or in an alternative embodiment, air enters from the outside through one or more valveless apertures in the outer tube (10). The entry of air in the intermediate chamber (7) helps the skirt (11) of the outer tube (10) to recover its original shape, as shown in fig. 14. The one-way valve (23) of the head (12) of the outer tube (10) prevents the product (51) or the outside air from returning to the inner space (22) of the head (12) of the outer tube (10) and thus towards the inner space (34,39) of the inner container (30). As a result, the inner container (30) is held in the deformed position, as shown in fig. 14. The fact that the sealing joint (40) between the shoulder (32) of the inner container (30) and the head (12) of the outer tube (10) is formed in the middle region of the head (12) of the outer tube (10) contributes to the fact that the deformed inner container (30) does not pull the non-deformed outer tube (10), so that both the inner container (30) and the outer tube (10) can easily maintain their deformed and non-deformed positions, respectively.

In other words, the tubular container (1) described previously is able to maintain its appearance intact after use (by recovering its undeformed appearance after pressing as shown in fig. 12 and 14), and also constitutes an airless container and has the associated advantages (mainly the product (51) remains isolated from the outside air, improving its preservation and prolonging its service life).

Repeated use of the tubular container (1) will cause the inner container (30) to be compressed more and more, while the outer tube (10) recovers as explained. Since the shoulder (32) is highly deformable and is connected to the head (12) of the outer tube (10) only by a sealed peripheral band (sealed joint (40)), the shoulder (32) can deform and fold almost freely inwards, resulting in a high level of collapse and reduction rate. If the edge (27) of the head (12) protrudes or has a seat in which the sealing joint (40) is located, the folding of the shoulder (32) with the skirt (31) of the inner container (30) when the product (51) is discharged is facilitated, further increasing the collapse of the inner container (30) and the reduction rate of the tubular container (1).

As previously mentioned, in an alternative embodiment, the intermediate chamber (7) communicates with the outside through one or more permanent apertures (i.e. permanently open apertures) in the outer tube (10), for example in the shoulder (17) or skirt (11) of the outer tube (10). This results in a less expensive tubular container, since there is no one-way valve (25) and assembly thereof is not required. The number and/or size of the orifices must provide an effective and comfortable balance between the loss of pressure through the intermediate chamber and the speed at which the outer tube returns to its original shape.

As for the materials for manufacturing the outer tube (10) and the inner container (30) of the tubular container (1), it has been mentioned so far that the outer tube (10) and the inner container (30) can be made of the following formulation: plastic materials, plastic composites, metal-plastic composites, one or more layers of textile materials, one or more layers of paper, combinations thereof, and the like. In short, it is contemplated that the outer tube (10) and inner container (30) may be made from any material or formulation suitable for flexible tubes of material, such as polypropylene, polyethylene, polyolefin copolymers, aluminum laminate composites, EVOH laminate composites, and the like. In a preferred embodiment of the invention, the outer tube (10) is made of a plastic formulation and is converted or formed using injection molding techniques, while the inner container (30) is preferably made of a plastic or metal-plastic formulation, more particularly a plastic or metal-plastic laminate composite material that is converted by forming techniques.

Preferably, the material or materials from which the inner container (30) is made meet one or more of the following requirements: impermeability requirements, Environmental Stress Crack Resistance (ESCR) requirements, delamination resistance requirements, food contact requirements, pharmacopoeia requirements, flexibility requirements, deformability requirements, and the like. This enables the inner container (30) to perform the functions described in this disclosure. While the outer tube (10) is made of one or more materials that meet one or more different requirements, such as workability requirements, surface appearance requirements, printability requirements (ability to print thereon), mechanical rigidity requirements (having a mechanical stiffness exceeding a threshold value), etc. In addition, one or more of the materials from which the outer tube (10) is made may be composed of recycled materials.

Preferably, the material or materials from which the outer tube (10) is made do not meet the requirements for the material or materials from which the inner container (30) is made. In other words, the outer tube (10) preferably does not meet the requirements for the inner container (30). For example, the material of the outer tube (10) preferably does not meet the impermeability requirements, Environmental Stress Crack Resistance (ESCR) resistance requirements, welding performance requirements, delamination resistance requirements, food contact requirements, pharmacopoeia requirements, flexibility requirements and/or deformability requirements that are met by the material of the inner container (30).

Preferably, the material or materials from which the inner vessel (30) is made do not meet the requirements for the material or materials from which the outer tube (10) is made. In other words, the inner container (30) preferably does not meet the requirements for the outer tube (10). For example, the material of the inner container (30) preferably does not meet the processability requirements, surface appearance requirements, printability requirements, mechanical rigidity requirements and/or weldability requirements that the material of the outer tube (10) does meet.

This separation of the functional requirements of the two parts, inner container (30) and outer tube (10), means that none of these parts have to meet all requirements simultaneously, thus facilitating the choice of materials for each tube. This simplifies the manufacture and improves the quality of the final tubular container (1) (quality is understood to be the ability of the tubular container (1) to meet its functional requirements during its service life).

In summary, the problem of incomplete recovery of the double tube unvented container is solved by using an inner container equipped with a skirt and a shoulder in the form of a wall with a decreasing diameter, which inner container is more deformable compared to the deformation of the inner tube head known in the prior art.

On the other hand, the problem of achieving a proper seal between the distal end of the outer tube and the distal end of the inner container disposed within the outer tube is solved by widening or expanding the distal end of the inner container outwardly until the distal end of the inner container is adjacent to and in contact with the distal end of the outer tube, and then sealing the two adjacent distal ends, thereby forming a tight joint between said distal ends along their entire circumference. It is contemplated that this solution may be used in tubular containers in place of the tubular containers shown herein, for example, in tubular containers in which both the outer tube and the inner container include respective skirts and respective headers.

Furthermore, the problem of the complexity of selecting materials is solved by forming a tubular container equipped with an inner container intended to remain hidden and in contact with the product to be stored, and an outer tube intended to be visible, wherein the material of each of these tubes meets different functional requirements, and most importantly, the outer tube does not meet the requirements for the inner container. It is contemplated that this solution may be used in tubular containers in place of the tubular containers shown herein, for example, in tubular containers in which both the outer tube and the inner container include respective skirts and respective headers.

Claims

1. A tubular container (1) of flexible material, comprising:

-an outer tube (10) having a skirt (11) and a head (12), wherein the skirt (11) has a proximal end (15) and a distal end (16), wherein the head (12) extends from the proximal end (15) of the skirt (11), and wherein the skirt (11) and the head (12) define an interior space (14,22), the interior space (14,22) being communicable with the exterior of the outer tube (10) through an aperture (21) in the head (12);

-an inner container (30), the inner container (30) having a skirt (31) and a flexible shoulder (32), wherein the skirt (31) has a proximal end (35) and a distal end (16), wherein the shoulder (32) extends from the proximal end (35) of the skirt (31), and wherein the skirt (31) and the shoulder (32) define an interior space (34,39), and the shoulder (32) terminates in a rim (38), wherein the rim (38) has a greater thickness than the remainder of the shoulder (32), and defines an aperture (37) communicating with the interior space (34, 39); wherein the content of the first and second substances,

-the inner container (30) is arranged in the inner space (14,22) of the outer tube (10) and the shoulder (32) of the inner container (30) is fixed to the head (12) of the outer tube (10) via a rim (38) by means of a sealing joint (40) in the middle region of the head (12), the aperture (21) of the head (12) of the outer tube (10) communicating with the inner space (34,39) of the inner container (30).

2. The tubular container (1) according to claim 1, characterized in that it comprises at least one-way valve (23) which enables fluid to leave the inner space (34,39) of the inner container (30) to the outside of the outer tube (10) and prevents air from entering the inner space (34,39) of the inner container from the outside of the outer tube (10).

3. The tubular container (1) according to claim 2, characterized in that said one-way valve (23) is arranged in an orifice (21) of the head (12) of the outer tube (10).

4. The tubular container (1) according to claim 1, characterized in that the skirt (31) of the inner container (30) does not protrude beyond the skirt (11) of the outer tube (10).

5. The tubular container (1) according to claim 1, characterized in that said sealing joint (40) extends continuously along the entire circumference around the central longitudinal axis (4) of the tubular container (1).

6. The tubular container (1) according to claim 1, characterized in that an intermediate cavity (7) is defined between the outer tube (10) and the inner container (30).

7. The tubular container (1) according to claim 6, characterized in that said sealing joint (40) extends continuously along the entire circumference around the central longitudinal axis (4) of the tubular container (1).

8. The tubular container (1) according to claim 7, characterized in that said intermediate cavity (7) is radially external to said sealing joint (40) with respect to said central longitudinal axis (4).

9. The tubular container (1) according to claim 8, characterized in that the shoulder (32) of the inner container (30) is connected to the head (12) of the outer tube (10) only along the sealing joint (40), with the remaining part of the shoulder (32) being radially external to the sealing joint (40) and separate from the outer tube (10).

10. The tubular container (1) according to claim 9, characterized in that said intermediate chamber (7) extends from said sealing joint (40) to the distal end (36) of the skirt (31) over the entire circumference of the skirt (31) and of the shoulder (32) around the central longitudinal axis (4) of the tubular container (1).